<template>
  <div>
    <h1>我是子元素</h1>
    <span>这个是子元素的{{ aa }}--{{ bb }}</span>
    <button @click="hclick">我是加一按钮</button>

  </div>
</template>
<script>

export default {
  props: {
    aa: {
      type: Number,
      required: true
    },
    bb: {
      type: Number,
      required: true
    }
  },
  methods: {
    hclick() {
      this.$emit('update:bb', this.bb + 1)
      this.$emit('update:aa', this.aa + 1)
    }
  }
}
</script>
